1. Field of the Invention
The present invention relates to an electrical connector for electrically connecting an electronic package such as a land grid array (LGA) chip with a circuit board such as a printed circuit board (PCB), and particularly to an LGA electrical connector with an operational lever and a lever retainer.
2. Description of Prior Art
Land grid array (LGA) electrical connectors are widely used in personal computer (PC) systems to electrically connect land grid array (LGA) chips with printed circuit boards (PCBs). An LGA electrical connector comprises an insulative housing, a multiplicity of terminals received in the housing in a rectangular array, a fastening frame surrounding the housing, a metal clip attached to the fastening frame, and an operational lever. U.S. Pat. No. 5,688,140 discloses this kind of conventional LGA electrical connector.
FIG. 6 shows a conventional LGA electrical connector 8 comprising an insulative housing 81, a multiplicity of conductive terminals 85 received in the housing 81, a fastening frame 82 surrounding the housing 81, a metal clip 84 attached to the fastening frame 82, and an operational lever 83 attached to the fastening frame 82. The clip 84 comprises two opposite pressing side plates 841, a first end plate 842, and a second end plate 843 opposite from the first end plate 842. A hook portion 8420 extends outwardly from a center of the first end plate 842. The second end plate 843 comprises a pair of pivot portions 8430 formed in opposite sides thereof. The lever 83 comprises an operational arm 830, a pair of pivot axles 831 perpendicularly extending from one end of the operational arm 830, and an offset pressing portion 832 between the two pivot axles 831. The housing 81 has a rectangular main body 810. The main body 810 defines a multiplicity of passageways 8101 arranged in a rectangular array, for receiving the corresponding terminals 85. A pair of opposite ends 812 extends from two diagonally opposite comers of the portion 810. A pair of mounting holes 8120 is defined in the ends 812 respectively, for fixing the housing 81 on a PCB (not shown).
The fastening frame 82 comprises a rectangular space 820 defined in a middle thereof, for accommodating an LGA chip 86. The space 820 is bounded by a first end portion 822, a second end portion 824 opposite from the first end portion 822, a first sidewall 823 interconnecting both the first end portion 822 and the second end portion 824, and a second sidewall 825 opposite from the first sidewall 823. A pair of first stepped holes 8220 is defined in opposite sides of the first end portion 822. A first arch-shaped projection 8222 protrudes from a junction of the first end portion 822 and the second sidewall 825. An arch-shaped slot 8226 is defined in the first projection 8222. A second arch-shaped projection 8224 protrudes from a junction of the first sidewall 823 and the first end portion 822. An arch-shaped guiding groove 8228 is defined in a bottom of the second projections 8224, in communication with the space 820. The slot 8226 and the groove 8228 are used for receiving the two pivot axles 831 of the lever 83 when the lever 83 is engaged with the fastening frame 82. A pair of second stepped holes 8240 is defined in the second end portion 824. The first and the second stepped holes 8220, 8240 are used for cooperatively fixing the fastening frame 82 on the PCB. A pair of arched pivot protrusions 8242 protrudes from opposite sides of the second end portion 824, for receiving the pivot portions 8430 of the clip 84. A cutout 8246 is defined in a middle of an inner side of the second end portion 824. A first resilient arm 8244 extends from the second end portion 824 adjacent the cutout 8246 to a point proximate to the second sidewall 825. The second sidewall 825 has a second resilient arm 8250 formed in an inner side thereof, proximate to the first resilient arm 8244. The first and the second resilient arms 8244, 8250 are used for fastening and releasing the LGA chip 86.
Referring to FIGS. 7 and 8, in use, the clip 84 is firstly oriented perpendicular to the fastening frame 82 in a first position. The lever 83 is oriented at a first position, with the pressing portion 832 being perpendicular to the fastening frame 82 and at a highest point. This enables the LGA chip 86 to be put into the fastening frame 82 for subsequent attachment to the housing 81 of the electrical connector 8. Then, the clip 84 is rotated to a horizontal second position, with the pressing side plates 841 abutting against the LGA chip 86. The operational arm 830 of the lever 83 is rotated to a second position, and the pressing portion 832 is retained in the hook portion 842 of the clip 84. Thus, the LGA chip 86 is stably fastened in the electrical connector 8. The LGA chip 86 is electrically connected with the terminals 85 received in the housing 81, and accordingly is electrically connected with the PCB.
In the electrical connector 8, the groove 8228 is in communication with the space 820 and a bottom of the fastening frame 82. Thus, the corresponding pivot axle 831 of the lever 83 can freely move in the groove 8228 of the frame 82 in directions both parallel to and perpendicular to the second projection 8224. In addition, there is no supplementary fixing structure between the fastening frame 82 and the lever 83. Accordingly, the lever 83 is easily disconnected from the fastening frame 82 in use of the electrical connector 8. This can result in failure of stable retention of the LGA chip 86 in the housing 81. This can further lead to disruption or failure of electrical connection between the LGA chip 86 and the PCB.
A new electrical connector that overcomes the above-mentioned problems is desired.
An object of the present invention is to provide an LGA electrical connector having a fastening frame with a retainer that facilitates stable and reliable connection of a lever to the fastening frame.
In order to achieve the above object, an LGA connector in accordance with a preferred embodiment of the present invention comprises an insulative housing, a multiplicity of terminals received in the housing, a fastening frame surrounding the housing, a metal clip pivotally mounted to the fastening frame, and a lever engaged with the fastening frame. The fastening frame comprises a base and a retainer formed separately from the base. The base includes a projection protruding from a junction of a first end portion and a first sidewall. The projection defines a guiding groove in a bottom thereof. A pair of receiving slots is defined in the projection at centers of two opposite inner sidewalls bounding the groove. The retainer comprises a first portion and a second portion perpendicular to the first portion. The second portion comprises a fastening slot adapted for receiving the lever in a top thereof, and a pair of protrusions protruding from central parts of two opposite sidewalls thereof. Each protrusion has an interference block protruding from an outer top side thereof. Each protrusion of the retainer is interferentially received in the corresponding slots of the base, for stably and firmly positioning the lever in the fastening frame.